(1) Field of the Invention
The present invention relates generally to the field of lighting and, more particularly, to a method and apparatus for providing light for fiber optic lights.
(2) Description of the Related Art
Conventional fiber optic light sources typically include a single incandescent light bulb or other single projection type lamp, which contains some sort of filament, like tungsten. Light is generated as the filament is heated. Thus, continuous lighting necessarily requires continuous heating of the filament. Due to the amount of heat generated, many conventional light sources have been considered unsafe when used with fiber optic instruments. U.S. Pat. No. 5,838,860 discloses a conventional “Fiber optic light source apparatus and method”. U.S. Pat. No. 5,803,575 discloses a conventional “Light generator for introducing light into optical fibers”. The full disclosures of these references are incorporated herein by reference.
Another problem with conventional fiber optic light sources is the negative effect that decomposition of the filament has on the interior glass of the lamp. As the filament decomposes, a layer of material is deposited on the interior glass of the lamp. As the layer of material accumulates, the layer acts as a filter, which absorbs the light and prevents it from traveling through the lamp. This effect invariably causes a significant decrease in the quality of light generated from the light source.
Another problem with conventional fiber optic light sources is that they typically cannot be efficiently dimmed. Incandescent lamps are black body radiators, i.e., the color of the light generated depends on the temperature of the filament. As the energy level to the filament is decreased, the filament temperature decreases, and the color of the light shifts more to the red end of the spectrum, which causes the light source to lose its effective visual spectrum color potential. The red-shifted effect in turn hinders accurate identification of color.
More advanced systems for providing light include U.S. Pat. No. 6,290,382, “Fiber bundle combiner and led illumination system and method”, U.S. Pat. No. 6,249,381, “Illuminating Method And Illuminating Device”, U.S. Pat. No. 6,022,123, “Light source device”, and U.S. Pat. No. 5,302,999, “Illumination Method, Illumination Apparatus And Projection Exposure Apparatus”. The full disclosures of these references are incorporated herein by reference.
There is, therefore, a need for an improved method and apparatus for providing light that overcomes the problems discussed above.